Analysis of the effects of an electric current on contact temperature, contact stresses and slip band initiation on the roller tracks of roller bearings

Abstract

An analysis has been carried out on the effects of an electric current on the rise in contact temperature between the rollers and the roller tracks of races and on contact stresses on the races leading to the initiation of slip bands and the formation of corrugations on the roller tracks of a roller bearing. Current passing through a bearing at the line contacts between the roller tracks and rollers, and the corresponding impedance were used to establish the amount of heat generated and the instant temperature rise in the contact zone on the roller tracks in each shaft revolution. By evaluating this temperature rise, the amplitude of the contact stresses was determined in order to calculate the number of cycles completed before slip bands are initiated on the roller track of the races. The number of cycles thus determined corresponds, within reasonable limits, to the appearance of slip bands on the roller track of the inner race of a roller bearing, operated under the influence of an electric current. This paper gives general guidance for the determination of the instant temperature rise and the duration of line contacts between the roller tracks of races and a roller in each shaft rotation, making it possible to predict the life of a roller bearing under the influence of an electric current before slip bands appear on the roller tracks.